SELECTED PHYSICAL AND AERODYNAMIC PROPERTIES OF AFRICAN BREADFRUIT (Treculia africana) SEEDS FROM SOUTH EASTERN NIGERIA

摘要

Physical and aerodynamic properties of African breadfruit () seeds were studied at four moisture levels: 12.50, 15.00, 17.50 and 20.10% dry base (w.b). As moisture content increased from 10.50 to 20.10% (w.b), the average weight, major diameter, minor diameter, intermediate diameter, geometric mean diameter, arithmetic mean diameter of the seeds ranged from 0.35±0.08 to 0.60g±0.04g, 8.08±0.90 to 10.05±0.60mm, 4.04±0.53 to 5.00±0.10mm, 2.96±0.43 to 4.60±0.40mm, 4.52±0.45 to 6.03±0.20mm, 5.03±0.45 to 6.55±0.50mm respectively. Also the equivalent diameter, surface area, sphericity, projected area and aspect ratio of the seeds ranged from 4.75±0.42 to 6.03±0.41mm, 64.19±12.64 to 114.25±10.00mm, 56±8.00 to 60±6.00%, 25.64±5.10 to 39.47 ± 3.80mm, and 50±0.08 to 50±0.01mm respectively. The volume ranged from 0.35 ± 0.014 to 0.73 ± 0.014cm, while the true and bulk densities ranged from 1.099 ± 0.141 to 1.110±0.424g/cm and 0.835±0.43 to 0.938±0.21g/cm. Porosity decreased from 15.01±1.5 to 5.60±0.4% as moisture content increased from 10.50 to 20.10% (w.b). The angle of repose ranged from 39.80 to 60.10 with increase in moisture content. The optimum parboiling time, temperature and moisture content for hulling African breadfruit seeds were determined as 7.5minutes, 57.5C and 20.10% (w.b) respectively. The terminal velocity of the seeds and kernels ranged from 12.5 to 17.02m/s and 11.40 to 13.36m/s. Drag coefficient and drag force of the hulls ranged from 0.1 to 0.7and 0.518×10to 0.858 ×10N, while the drag coefficient and drag force of the seeds and kernels ranged from 0.09 to 0.2, 4.50 ×10 to 6.00×10N; 0.2 to 0.3 and 4.0×10 to 5.10×10N respectively. This indicates that optimum separation can be achieved effectively without any loss of the seeds ifthe results obtained are properly applied in processing of African breadfruit.